First mosquitoes test negative for EEE, West Nile virus

Tuesday

Jul 1, 2014 at 11:25 PMJul 2, 2014 at 5:54 PM

The Taunton-based Bristol County Mosquito Control has started collecting samples and receiving their first results, yielding no positive tests thus far for eastern equine encephalitis or West Nile virus.

But it’s only a matter of time, said Jennifer Dacey, director of the local agency, which collects mosquito samples and provides ground spraying of insecticides to battle the bugs.

“We haven’t had any positives yet, but we do expect that to change because history has told us that,” Dacey said. “It’s just a matter of time before we start getting positives. … It’s hard to predict what the season is going to be like. It’s good if things stay dry. Hopefully, it won’t be as bad.”

A Department of Public Health risk map for eastern equine encephalitis, or EEE, shows that the risk throughout Bristol County is now “low,” with the exception of Dighton, Easton and Raynham, which is at “moderate.” Dacey said this is partly based on the results from last year.

Last year, the Bristol County Mosquito Control collected 29 positive samples of EEE-infected mosquitoes, in addition to 79 positives for West Nile virus. Of those numbers, the most were collected in Easton (10), followed by Dighton (6) and Raynham (3). Raynham also had 13 positives for West Nile last year, the highest of the towns in the county.

The Bristol County Mosquito Control Project works out of a Taunton office, where it collects mosquito samples, examines them and then sends them out for laboratory testing.

Dacey said that in recent years the EEE findings have been high, trending much more frequently than in prior decades. She said that Raynham and Easton are hot spots because of how close they are to swamps where the disease develops.

“The last few years it certainly has increased,” Dacey said. “God, 10 years ago we didn’t have those types of results and the amount of requests (for ground spraying). … It’s (in those towns more frequently) because their proximity to the Dead Swamp and the Pine Swamp and the Hockomock Swamp. They also have catch basins containers, places that the West Nile breeds. It’s not only the swamps. It’s in people’s back yards and different habitats.”

The last human death in the county from EEE was Martin Newfield, who died in Raynham in 2011, Dacey said.

Newfield’s death prompted health officials in Raynham to become vocal about the need for aerial spraying of insecticides by the state to combat EEE. Town officials also curtailed public events in the town at night to reduce risk, and strongly encouraged personal safety measures, like using bug spray and reducing skin exposure when outdoors.

After several public forums about the issue, DPH decided to study the matter and updated its protocols for EEE surveillance and spraying. The use of the aerial spraying of adult insecticide must be approved each time by DPH, after it finds EEE at a high enough level.

However, Raynham officials like Selectman Joseph Pacheco continue to call for “preventative” aerial spraying. The Raynham Board of Selectmen made a motion last month to make another request to DPH for conduct “frequent and aggressive” spraying to combat the EEE risk.

“We always felt it needs to be done early in the season,” Pacheco said. “DPH acknowledged recently that EEE is now part of our region, that we expect it every year. We already knew that. … Now that they have acknowledged it, we have to take those extra measures to start combating that. Part of that is aggressive aerial spraying.”

Earlier this year, the Bristol County Mosquito Control and the Plymouth County Mosquito Control projects teamed up to take things in their own hands by using planes to drop larvicide on swamp areas where mosquitoes grow.

Dacey said that dry weather would be good to keep the EEE threat level down, but if the threat level increases, aerial spraying may be a solution to reduce the threat.

“If we start getting positives the way we have the last few years, what DPH has to do is assess it and there has to be a need for it,” she said. “If testing shows a great deal of positives, it might be a good idea.”